Helleborus plant named ‘COSEH 3090’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 3090’, characterized by its upright and mounding plant habit; uniform and freely flowering habit; dark green-colored leaves; freely and early flowering habit; single white-colored flowers; and good garden performance.

Botanical designation: Helleborus niger.

Cultivar denomination: ‘COSEH 3090’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofHelleborus plant, botanically known as Helleborus niger and hereinafterreferred to by the name ‘COSEH 3090’.

The new Helleborus plant is a product of a planned breeding programconducted by the Inventor in Glandorf, Germany. The objective of thebreeding program was to create new uniform Helleborus plants with uniqueand attractive plant habit, leaf and flower coloration and resistance topests common to Helleborus plants.

The new Helleborus plant originated from a cross-pollination conductedby the Inventor in Glandorf, Germany in November, 2008 of two unnamedproprietary seedling selections of Helleborus niger, not patented. Thenew Helleborus plant was discovered and selected by the Inventor as asingle flowering plant from within the progeny of the statedcross-pollination grown in a controlled greenhouse environment inGlandorf, Germany in December, 2010.

Asexual reproduction of the new Helleborus plant by divisions in acontrolled environment in Glandorf, Germany since February, 2011 hasshown that the unique features of this new Helleborus plant are stableand reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possiblecombinations of environmental conditions and cultural practices. Thephenotype may vary somewhat with variations in environmental conditionssuch as temperature and light intensity without, however, any variancein genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘COSEH 3090’. These characteristics incombination distinguish ‘COSEH 3090’ as a new and distinct Helleborusplant:

-   -   1. Upright and mounding plant habit.    -   2. Uniform and freely flowering habit.    -   3. Dark green-colored leaves.    -   4. Freely and early flowering habit.    -   5. Single white-colored flowers.    -   6. Good garden performance.

Compared to plants of the parent selections, plants of the newHelleborus are more uniform and more freely flowering.

Plants of the new Helleborus can be compared to plants of Helleborusniger ‘HGC Josef Lemper’, disclosed in U.S. Plant Pat. No. 15,615. Inside-by-side comparisons, plants of the new Helleborus differ primarilyfrom plants of ‘HGC Josef Lemper’ in the following characteristics:

-   -   1. Plants of the new Helleborus have smaller flowers than plants        of plants of ‘HGC Josef Lemper’.    -   2. Plants of the new Helleborus flower earlier than plants of        ‘HGC Josef Lemper’.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Helleborus plant showing the colors as true as it isreasonably possible to obtain in colored reproductions of this type.Colors in the photographs may differ slightly from the color valuescited in the detailed botanical description which accurately describethe colors of the new Helleborus plant.

The photograph on the first sheet is a side perspective view of atypical flowering plant of ‘COSEH 3090’ grown in a container.

The photograph on the second sheet is a close-up view of a typicalflower of ‘COSEH 3090’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurementsand values describe plants grown during the autumn in 13-cm containersin a glass-covered greenhouse in Glandorf, Germany and under culturalpractices typical of commercial Helleborus production. During theproduction of the plants, day temperatures ranged from 12° C. to 32° C.and night temperatures ranged from 3° C. to 18° C. Plants were 14 monthsold when the photographs and the description were taken. In thefollowing description, color references are made to The RoyalHorticultural Society Colour Chart, 2015 Edition, except where generalterms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus niger ‘COSEH 3090’.-   Parentage:    -   -   Female, or seed, parent.—Unnamed proprietary seedling            selection of Helleborus niger, not patented.        -   Male, or pollen, parent.—Unnamed proprietary seedling            selection of Helleborus niger, not patented.-   Propagation:    -   -   Type.—By tissue culture.        -   Time to initiate roots, winter.—About two months at            temperatures about 12° C.        -   Time to produce a rooted young plant, winter.—About six            months at temperatures ranging from 4° C. to 15° C.        -   Root description.—Thick to thin, fleshy; typically white to            brown in color, actual color of the roots is dependent on            substrate composition, water quality, fertilizer type and            formulation, substrate temperature and physiological age of            roots.        -   Rooting habit.—Sparse.-   Plant description:    -   -   Plant and growth habit.—Herbaceous perennial; upright and            mounding plant habit with flowers held above the foliar            plane; plant shape, roughly flattened globular; low vigor to            moderately vigorous growth habit; slow to moderate growth            rate.        -   Plant height, soil level to top of foliar plane.—About 15.1            cm.        -   Plant height, soil level to top of flowers.—About 28.2 cm.        -   Plant diameter (area of spread).—About 30 cm.-   Leaf description:    -   -   Arrangement.—Leaves arranged in a basal rosette; leaves            palmately compound with typically seven leaflets per leaf.        -   Leaf length.—About 11.4 cm.        -   Leaf width.—About 12.1 cm.        -   Leaflet length.—About 7.3 cm.        -   Leaflet width.—About 3.5 cm.        -   Leaf shape.—Palmate; reniform in outline.        -   Leaflet shape.—Obovate.        -   Leaflet apex.—Abruptly acute.        -   Leaflet base.—Attenuate.        -   Leaflet margin.—Serrate.        -   Leaflet texture and luster, upper surface.—Smooth, glabrous;            slightly rugose; glossy.        -   Leaflet texture and luster, lower surface.—Smooth, glabrous;            slightly rugose; slightly glossy.        -   Leaflet venation pattern.—Pinnate.        -   Leaflet color.—Developing leaflets, upper surface: Close to            between NN137B and 147A. Developing leaflets, lower surface:            Close to between 138A and 138B. Fully developed leaflets,            upper surface: Close to darker than between NN137A and 147A;            venation, close to 137B to 137C. Fully developed leaflets,            lower surface: Close to 144A; venation, close to 144B.        -   Petioles.—Length: About 8.9 cm. Diameter: About 6 mm.            Strength: Strong. Texture and luster, upper and lower            surfaces: Smooth, glabrous; slightly glossy. Color, upper            and lower surfaces: Close to 144B heavily tinged and            speckled with close to 177A.-   Flower description:    -   -   Flower shape and habit.—Single rotate flowers arranged            solitary or in pairs; freely and uniform flowering habit            with about 22 flowers developing per plant; flowers facing            outwardly to slightly nodding.        -   Fragrance.—None detected.        -   Natural flowering season.—Plants begin flowering about ten            months after planting; plants flower from autumn into winter            in Germany.        -   Flower longevity on the plant.—About ten days; flowers not            persistent.        -   Flower buds.—Length: About 2.1 cm. Diameter: About 1.3 cm.            Shape: Ovate. Texture and luster: Glabrous; matte. Color:            Close to NN155D.        -   Flower diameter.—About 7.4 cm.        -   Flower depth (height).—About 2.3 cm.        -   Petals.—Transformed into nectaries.        -   Sepals.—Quantity and arrangement: Five, arranged in a single            whorl. Length: About 3.7 cm. Width: About 3.1 cm. Shape:            Broadly ovate. Apex: Obtuse. Base: Cuneate. Margin: Entire.            Texture and luster, upper and lower surfaces: Glabrous;            matte. Color: When opening, upper and lower surfaces: Close            to NN155B. Fully opened, upper and lower surfaces: Close to            NN155B; towards the base, close to 150D.        -   Flower bracts.—Quantity per flower: Typically one. Length:            About 3.3 cm. Width: About 2.6 cm. Shape: Ovate. Apex:            Acute. Base: Broadly cuneate. Margin: Entire; slightly            undulate. Color, upper surface: Close to 138A. Color, lower            surface: Close to 138B.        -   Peduncles.—Length: About 20.6 cm. Diameter: About 5 mm.            Aspect: About 20° from vertical. Strength: Moderately            strong. Texture and luster: Glabrous; slightly glossy.            Color: Close to 144B to 144C, heavily tinged and speckled            with close to 174A.        -   Pedicels.—Length: About 9 cm. Diameter: About 3 mm. Aspect:            About 25° from peduncle axis. Strength: Moderately strong.            Texture and luster: Glabrous; glossy. Color: Close to 144B            to 144C, heavily tinged and speckled with close to 174A.        -   Reproductive organs.—Stamens: Quantity per flower: About 70.            Filament length: About 1.3 cm. Filament color: Close to            NN155D. Anther shape: Reniform; basifixed. Anther size:            About 1.5 mm by 2 mm. Anther color: Close to 3C. Pollen            amount: Moderate to abundant. Pollen color: Close to 2D.            Pistils: Quantity per flower: About nine. Pistil length:            About 1 cm. Stigma diameter: About 0.3 mm. Stigma shape:            Club-shaped. Stigma color: Close to 148D. Style length:            About 9.5 mm. Style color: Close to NN155A. Ovary color:            Close to slightly lighter than 157D. Nectaries (transformed            petals): Quantity per flower: About 20. Length: About 1 cm.            Diameter: About 3.5 mm. Shape: Tubular, flattened. Texture            and luster, inner surface: Smooth, glabrous; matte. Texture            and luster, outer surface: Smooth, glabrous; glossy. Color,            immature, inner and outer surfaces: Close to N144D; towards            the apex, close to 1B. Color, mature, inner and outer            surfaces: Close to 144B; towards the apex, close to 2D.        -   Seeds and fruits.—Seed and fruit development have not been            observed on plants of the new Helleborus.-   Garden performance: Plants of the new Helleborus have been observed    to have good garden performance and to tolerate rain, wind and to be    suitable for USDA Hardiness Zones 5 through 9.-   Pathogen & pest resistance: Plants of the new Helleborus have not    been observed to be resistant to pathogens and pests common to    Helleborus plants.

It is claimed:
 1. A new and distinct Helleborus plant named ‘COSEH 3090’ as illustrated and described. 